罗尼(文斯·沃恩 Vince Vaughn 饰)和尼克(凯文·詹姆斯 Kevin James 饰)是一对关系十分要好的死党,从大学时代一路陪伴进入职场,他们似乎是世界上最熟悉彼此的存在。不仅如此,罗尼的女友贝丝(詹妮弗·康纳利 Jennifer Connelly 饰)和尼克的妻子吉妮瓦(薇诺娜·瑞德 Winona Ryder 饰)也是一对无话不谈的好朋友。 故事要从罗尼在街上偶遇吉妮瓦的那一天说起,要命的是,那一天和吉妮瓦亲密的站在一起的却并非她的丈夫,亦是罗尼的好友尼克,而是另一个他并不认识的英俊男人。这件事情成为了罗尼的心结,在友情和道义面前,罗尼不知该如何选择。更让罗尼震惊的是,他逐渐发现尼克竟然也有着不能对他倾诉的秘密。A man finds out that what you don't say to a friend is just as important as what you do is this story of how far you can bend a brotherly bond before it snaps. Since college, confirmed bachelor Ronny (Vaughn) and happily married Nick (James) have been through thick and thin. Now partners in an auto design firm, the two pals are vying to land a dream project that would launch their company. Ronny's girlfriend, Beth (Connelly), and Nick's wife, Geneva (Ryder), are by their sides. But Ronny's world is turned upside down when he inadvertently sees Geneva out with another man and makes it his mission to get answers. As the amateur investigation dissolves into mayhem, he learns that Nick has a few secrets of his own. Now, with the clock ticking and pressure mounting on the biggest presentation of their careers, Ronny must decide what will happen if he reveals the truth to his best friend.